A.A study to examine the relationship between stock prices and interest rates on company revenue

B.A study to examine the relationship between average salary and age of buyer on the amount spent on housing

C.A study to examine the relationship between age and weight on the probability of breast cancer

D.A study to examine the relationship between the season and amount of water pollution on the number of sea-turtles

A.In the long-run restaurants make zero economic profit.

B.In the short-run restaurants make zero economic profit.

C.A mobile food truck has lower fixed costs than a restaurant.

D.A mobile food truck invites a wider variety of customers than a restaurant.